English
If hlb is a basis for lb, then Tendsto f la lb is equivalent to: for each i, pb i implies f x ∈ sb i eventually for x in la.
Русский
Если hlb — базис lb, то Tendsto f la lb эквивалентно: для каждого i, pb i следует f x ∈ sb i часто в la.
LaTeX
$$$ \mathrm{Tendsto} f\ la lb \iff \forall i,\ pb(i) \to \forall^\infty x in la, f(x) \in sb(i) $$$
Lean4
theorem tendsto_right_iff (hlb : lb.HasBasis pb sb) : Tendsto f la lb ↔ ∀ i, pb i → ∀ᶠ x in la, f x ∈ sb i := by
simp only [Tendsto, hlb.ge_iff, mem_map', Filter.Eventually]